During the comet's run into the closer part of the solar system for the first time in 500,000 years, the nucleus of Comet West was seen to split into four pieces as it passed within 30 million km. of the sun.

The first report of the split came around 7 March 1976 12:30UT, when reports were received that the comet had broken into two pieces. These two pieces remained the only pieces until Steven O'Meara, using the 9-inch Harvard Refractor, reported that two additional pieces had formed on the morning of 18 March.

The breakup was one of very few comet breakups seen from historical times by the 1970s. Recently, comets Shoemaker-Levy 9, Schwassmann-Wachmann-3 (73/P), C/1999 S4 LINEAR, and 57/P du Toit-Neujmin-Delporte, have been seen to disintegrate. When seen, many were stunned, but none more so than the discoverer, Richard Martin West. The comet broke into pieces when some distance from the sun. It exploded into four pieces, and those were scattered. Later, two pieces were spotted, and studied intently by astronomers.